Some rules

This could be a very dull read for anyone who dislikes the grammatical workings of the English language. But I rather like grammar and proper English, so I want to elucidate the correct way to employ some commonly misused words found in our native tongue.

"There is" vs. "There are"
-"There is" precedes a singular noun - "BEHOLD! THERE IS A UFO!"
-"There are" precedes a plural noun. - "There are many kinds of fish; my favorite is the piranha."

Less vs. Fewer
-"Less" describes something qualitative - "There is less lemonade in my glass, because my cat spilled it on my homework. Now I can't turn in the assignment."
-"Fewer" describes something quantitative - "There are fewer cookies in the jar, because I ate all of them except one."

Their/They're/There
-"Their" is possessive - "The llama belongs to them. It is their own."
-"They're" is a conjunction for "they are" - "They're going to travel around Europe, trying to break the world record of 'Most churches attended in one day.'"
-"There" means a specific place - "Put the thurible down over there."

Ensure vs. Insure vs. Assure
-"Ensure" means "to guarantee, to make certain" - "It is the responsibility of parents to ensure that children are trained in the way they should go.'"
-"Insure" means "to make certain by employing precautions" - "I have pre-cooked the bacon to insure that the pancake breakfast will be satisfying to all participants."
-"Assure" means "to make certain by setting the mind at rest" - "I can assure you that all is well with the world."

Affect vs. Effect
-"Affect" is a verb - "The pungent smell from the nearby barn affected the enjoyment of the chocolate-tasting party."
-"Effect" is a noun - "The effect was absolute anarchy and disaster."

If I write anymore, the world might fall asleep. No one likes mass narcolepsy. I've left out which vs. that, your vs. you're, elicit vs. illicit, than vs. then, and accept vs. except, but I think, if in doubt, one can always Google. However, no one (including myself) can have any excuse to misuse these words anymore. Ever. Exeunt.